Hair straightener



FIG. 1 is a front and top perspective view of a hair straightener, showing my new design;

FIG. 2 is a rear and bottom perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a top plan view thereof;

FIG. 8 is a bottom plan view thereof;

FIG. 9 is an enlarged view of a portion indicated with numeric 9 in FIG. 1;

FIG. 10 is an enlarged view of a portion indicated with numeric 10 in FIG. 1; and,

FIG. 11 is an enlarged view of FIG. 8.

The dash-dot-dash lines in FIGS. 1, 9 and 10 are for the purpose of illustrating enlarged view indicators and form no part of the claim. The evenly-spaced broken lines in the figures illustrate portions of the hair straightener that form no part of the claimed design. 

CLAIM The ornamental design for a hair straightener, as shown and described. 